If the trader is flying a transport, the first thing I do is to look to the tag. If its white or red, I hit the trade button request and start shooting the trader. If the tag is green, then I scan the cargo to see if he is carrying a friendly ID. If the trader is not flying a transport but a freighter, I scan his cargo to see if he carries a neutral ID, because you known, some crying babies uses this ID for trading.
If Im alone, I dont hunt the trader for more than one jump. If Im grouped with someone, I can try two jumps, since with more people we can coordinate the attack separating the group, each one going in one direction. If theres no more traders in the system or in neighboring systems, I dock and log out.
